Process of blowing off the necks of lamp-bulbs.



No. 818,674. PATENTED APR. 24, 1906.

E. L. ELLIOTT.

PROCESS OF BLOWING OFF THE NECKS OF LAMP BULBS. APPLIOATION FILED SEPT.12,1904.

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UNITED STATES PATENT OFFICE.

ELIAs L. ELLIOTT, OF CLEVELAND, I-IIO, ASSIGNOR TO THE BRILLIANT ELECTRIC COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

Specification of Letters Patent.

Patented April 24, 1906.

Application filed September 12. 1904. Serial No. 224.064.

To all whom it may concern:

Be it known that I, ELIAs L. ELLIOTT, a citizen of the United States, residing at Cleveland, in the county of Ouyahoga and State of Ohio, have invented a certain new and useful Improvement in Processes of Blowing Off the Necks of Lamp-Bulbs, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings.

Incandescent-lam bulbs as generally furnished by the glasslowers have a comparatively long ortion of glass tubing upon the open end w ich was utilized in blowing the bulb. It is necessary to remove a portion of this neck portion, asitis called, to make it of the proper length when the base is a plied to the lamp and to also flange out tie lower edge in a manner such that the filament when being supplied to the lamp may be readily inserted through this neck portion without injury. This process is what is termed the blowing-off process. Heretofore such processes have been more or less crude and unsatisfactory and have also consumed a great deal of time, and since the saving of time is a great factor in the manufacture of these lamps any time-saver is of vital importance.

This invention therefore broadly speaking, relates to the process of blowing off these neck portions from the lamps and rendering the portion remaining upon the lamp in a flared condition, so that the filament will be readily applied without injury to it.

More specifically the invention relates to the process of first subjecting the neck portion of the lamp-bulb to the influence of heat furnished by suitable burners, then rotating the bulb in such flame until the neck portion is finally blown off and the portion thereof which remains upon the bulb closed, thus resulting in such portion becoming expanded by the ex ansion of the air within the bulb, and final y continuin the rotation of the bulb such that the soft portions of the glass about the remaining cylindrical portion will be spread or flared out to readily admit the filament when inserted in the bulb.

Referring to the drawings, Figure 1 is a side elevation, partially in section, showing a suitable apparatus for carrying out my improved process. Fig. 2 is a side elevation of a bulb after it has been rotated and subjected to the heat of the flame. Fig. 3 is a further development of the lamp-bulb under the same conditions. Fig. 4 is a still further development after the lower end of the bulb has been closed and has been expanded by the heated air within the bulb, and Fig. 5 shows a finished bulb with its lower neck portion flared out to receive the filament.

The apparatus shown (which is to be taken as illustrative of any apparatus for carrying on the process) consists of a base A, having a bearing a and a bracket provided with a bearing a. In these two bearings is rotatably mounted a hollow shaft B, to which is keyed a driving-pulley 1) between the bearing a and a. and a frame member I), secured thereto by a screw 1), whereby it will rotate with the shaft. Rigidly secured to this frame member I) are suitable upright rods 1), supporting an upper disk I) and a socket b which just fits the lower portion 0 of the bulb O and has an opening therein for the reception of the neck portion 6 of the bulb. hollow shaft has a bore of sufficient size to receive this neck portion 0 of the lam -bulb as it comes from the glass-blowers, w iereby when a lamp-bulb is placed in the socket b the cylindrical portion 0' will extend through into the hollow shaft B. Suitable means is provided for retaining the bulb in the socket and this means consists of a standard D, secured to the base and having an arm d at its upper end extending over to a point on a line with the axis of the hollow shaft B, where it is provided with a shank (2, having thereon a spider (1 whose fingers d are arranged to en age the upper portion of the bulb O and he ding it down in the socket b A drivingbelt E passes around the driving-pulley ti and is connected with any suitable source of ower (not shown) for first rotating the holow shaft.

Any suitable means may be provided for heating the glass portion of the bulb, and I have shown a very common and well-known construction which consists of the burners F and F, diametrically o posed to each other with respect to the nec portion of the bulb and connected to a gas-sup ly ipe Airjets G and (r are provided for b owing these gas-flames, and these jets are connected with a source of supply g.

A description will now be given of the The process as it is carried on and the operation of the apparatus shown.

The lamp-bulbs are blown in the glass factory in substantially the form shown in Fig. 2

. with a comparatively long tubular neck portion at the ase. This neck ortion has to be blown off and flared, as be ore stated. To bring about this result, the s ider d is raised and the ortion c of the ulb is inserted through t e socket b into the opening of the hollow shaft B, the gas-jets having been previously lighted and the air-blast arranged to direct the sharp-pointed flames in a direction to engage suchneck ortion. The hollow shaft is then rotated by t e belt E, and as the glass of the tubular neck ortion becomes heated it will assume the con guration shown in Fig. 2 or, in other words, will contract along the heated band, and this contraction will.continue until the weight of the lower part of this neck portion will pull away from that remaining on the bulb, which has in the meantime become sealed, as shown in Fig. 3. The air in the bulb is necessarily expanding all the time, as the heat is applied at the lower end, and such expansion results either in the blowing of a bubble o as shown in Fig. 4, or in the opening of the lower end of the bulb.

, The bulb is then rotated at such a speed that the soft glass which has been blown out by the expansion of the air within the bulb is spread or flared into the configuration shown in Fig. 5 bythe centrifugal force which has been brought to bear upon it by the rotation of the bulb. The bulb is then ready for the insertion of the filament.

The speed of the bulb may be the same during both the heating and flaring o erations, though I have found that revo ving the bulb slowly during the heating and until the neck of the bulb drops off and then revolving at a higher speed to flare out gives consists in first melting off'the Waste portion and softening the edge of the remaining 7 ortion thereof, and rapidly rotating the bul to spread or flare out such softened edge.

2. The herein-described process of blowing off the neck portion of lam -bulbs, which consists in first revolvin suc bulb in suitable flames to melt off t e Waste portion of the tube therefrom and thereby softening the edge of the remaining portion, and then continuing to rotate said bulb in a manner such that the softened edge will be spread or flared out by centrifugal force.

3. The herein-d escribed process of blowing sists in first melting off the waste portion thereof by revolving it in suitable flames and softening the ed e of the'remaining portion, and continuing t e rotation to spread or flare out such softened edge.

4. The herein-described process of blowing off the neck portion of lamp-bulbs which consists in rotating the bulb with its neck portion in suitable gas flames whereby the waste portion is permitted to blow off by gravity and the lower edge of the bulb is left soft, and in continuing to rotate said bulb whereby the soft glass is spreader flared out.

In testimony whereof I hereunto affix my signature in the presence of two witnesses.

ELIAS L. ELLIOTT.

Witnesses: C. F. SMIEDEL, B. W. BROCKETT.

' off the neck portion of lamp-bulbs, which con- 

